A brazing sheet containing an aluminum alloy (hereinafter sometimes simply referred to as an “Al alloy”) having a brazing filler material and a sacrificial material provided on one surface or both surfaces of a core material (such a brazing sheet is hereinafter sometimes simply referred to as a “brazing sheet”) is conventionally used as a material for heat exchangers of automobiles and the like.
In recent years, weight reduction of automotive heat exchangers is strongly demanded, and further thickness reduction is required in a brazing sheet. It is necessary for the thickness reduction to increase tensile strength of a brazing sheet after brazing. For this reason, an aluminum alloy having excellent tensile strength, such as an Al—Si—Cu—Mn alloy and an alloy having Mg further added thereto, are developed as a core material of a brazing sheet.
For example, Patent Literature 1 discloses a brazing sheet having excellent tensile strength after brazing, using an Al—Si—Fe—Cu—Mn—Mg alloy as a core material of a brazing sheet.